In our co-pending parent application their is disclosed a drill sharpener which produces the required configuration of movements at the cutting end of twist drills during the sharpening operation to quickly, accurately, and simultaneously grind and sharpen the cutting lips of two, three, four, etc. flute twist drills to any preferred drill point angle, to any preferred lip relief angle, to any preferred chisel angle, and very accurately locate the center of the chisel point with the center of the drill, by simply manually rotating a chuck containing the drill in a fixture as the cutting end of the drill is manually pressed against the face of a rotating grinding wheel.
The assembly includes a separately handled drill chuck having four jaws long enough to span the full length of one complete spiral of the flutes of the drill which for a 1/2 inch diameter drill with a standard helix angle is 2 and seveneighths inches long, and grip the drill close enough to the point to prevent vibration during the grinding operation. The drill chuck mounts two cams integral with each other which are normally free to rotate on the chuck but by the use of a clutch tightened by a hand knob are clutched to the chuck after the drill is clamped by the four jaws.